Acanthamoeba keratitis successfully treated with penetrating keratoplasty: suggested immunogenic mechanisms of action.

A patient with a corneal ulcer caused by Acanthamoeba polyphaga has been successfully treated with a penetrating keratoplasty. The pathologic specimen showed no inflammatory infiltrate surrounding the intact amoeba, whereas necrotic organisms were surrounded by an intense cellular reaction. Indirect immunochemical studies showed that the trophozoite stained profusely, but the cyst form exhibited the antigenic site on the cyst wall.